[test] Widen ownership of test status files.

Change-Id: I45ee52b4eb4729969f2ebb707a95ea44ecd0c10d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/236243
Reviewed-by: Alexander Thomas <athom@google.com>
Commit-Queue: William Hesse <whesse@google.com>

pkg/OWNERS

@@ -1,2 +1,5 @@
 file:/tools/OWNERS_FOUNDATION #{LAST_RESORT_SUGGESTION}
 file:/tools/OWNERS_INFRA #{LAST_RESORT_SUGGESTION}
+
+# Test status file
+per-file pkg.status=file:/tools/OWNERS_ENG

third_party/pkg_tested/OWNERS

@@ -0,0 +1,2 @@
+# Test status file
+per-file pkg_tested.status=file:/tools/OWNERS_ENG